Ellen DeGeneres popularized it at the Oscars. Oxford Dictionary made it the hottest word of 2013.

Now the trendiest pose, the selfie, has conquered graduation ceremonies. But school officials are not so enthusiastic.

At Elk Grove High School, administrators temporarily withheld the diplomas of two graduates for taking selfies as they walked across the stage last Tuesday at the school’s graduation ceremony.

Administrators called the photo-snapping “inappropriate behavior.”

Elizabeth Graswich, spokeswoman for the Elk Grove Unified School District, said all students were warned not to take selfies at graduation, and the boys who were disciplined received an additional warning as they prepared to mount the stage.

Graswich said beach balls have caused disruptions at past graduations and school officials merely wanted to preserve the dignity of the event. If everybody stopped to take a selfie, she said, it would slow the progress of graduates across the stage, and turn long ceremonies into marathons.

“We want everyone graduating and in attendance to enjoy the ceremony,” Graswich said.

Though their classmates at Elk Grove High School picked up their diplomas on Tuesday, the two boys who were disciplined had to wait until Thursday to receive theirs, Graswich said.

Reached by The Bee, the parents of one of the boys, Jack Budmark, said they accepted the punishment. They declined to have their son be interviewed.

“We respect the (school’s) authority,” said Tres Johnson, Jack’s stepfather. “We feel that they acted within their bounds and thought it was fine.”

“Jack graduated; we’re happy,” said his mother, Marie Manzer.

Elk Grove High is one of many schools nationwide trying to quash the notion that the commencement stage is an appropriate place to pause for a self-portrait. Earlier this spring, Bryant University in Rhode Island and the University of South Florida made news when they asked students to refrain from taking selfies. USF even published an ad in the school’s newspaper with a list of inappropriate behaviors under the headline “Graduation Etiquette.”

Some schools, including Kent State University in Ohio, have tried to contain selfies by setting up special social media zones where students are encouraged to take pictures, tweet and post photos to Instagram.

Other schools have embraced the selfie. At the University of Cincinnati graduation this year, President Santa J. Ono posed onstage with seniors.

Jesse Drew, an associate professor of cinema and technocultural studies at UC Davis, said the selfie is a natural outgrowth of the rise of social media sites such as Instagram and Facebook, which give young people a tool to call attention to themselves.

“The selfie allows them to take control of their own personality,” Drew said.

Drew said he thinks school administrators have a right to ban selfies if they want to but added that he thought the punishment meted out by Elk Grove High School was “pretty draconian.”

There is a fine line between having a celebratory “selfie moment” and “behaving inappropriately,” said Jorie Scholnik, an expert in millennial etiquette and student development at Santa Fe College in Gainesville, Fla.

“I think it crosses the line when it becomes disruptive,” Scholnik said. “Colleges and families have sacrificed a lot and put in a lot of hours for this occasion.”

Regardless of whether school districts have a strict policy against posting selfies or tweeting the grand achievements, there’s not much faculty can do to stop it, said Trent Allen, spokesman for San Juan Unified School District in Sacramento.

SJUSD does not have a guiding principle on social media at graduation ceremonies, but Allen said, as long as there are no disruptions, “We don’t see it as a big deal.”